On Early Earth,more Than 4 Billion Years Ago,environmental Conditions Were

Multiple Choice

On early Earth,more than 4 billion years ago,environmental conditions were very different from those today because

A) only early Earth was intensely bombarded by large rocks and ice from space.
B) only early Earth had an oxidizing atmosphere.
C) less ultraviolet radiation penetrated early Earth's atmosphere.
D) early Earth's atmosphere had significant quantities of ozone.